tbuckley/cabot-search huggingface dataset:
Abstract 4746: Amelioration of hemoglobinopathies by targeted deletion of zinc finger domain within <i>BCL11A</i> gene using CRISPR-Cas9 technology
Authors: Irfan Hussain, Kainaat Mumtaz, Hammad Hassan, Afsar Ali Mian
Journal: Cancer Research (2023)

Abstract Background: In humans, the β-like globin genes are encoded from a single locus comprising five globin genes (ε-, Gγ-, Aγ-, δ-, and β-globin in sequence) and their expression is under developmental control. The γ-globin genes (Gγ- and Aγ-) are expressed during fetal life and replaced by adult β-globin after birth. Mutations in the β-globin gene cause β-hemoglobinopathies such as sickle cell disease (SCD) and β-thalassemia. The clinical severity of SCD and β-thalassemia can be mitigated by elevated fetal hemoglobin (HbF) levels, which have been found in individuals with the benign hereditary persistence of fetal hemoglobin (HPFH) syndrome. Thus, reactivating the expression of γ-globin genes is an attractive treatment strategy for β-hemoglobinopathies. Reactivation of γ-globin expression by disrupting the binding of the BCL11A transcriptional repressor complex to the γ-globin gene promoter, provides a novel approach for inducing fetal hemoglobin. Methodology: The BCL11A binds a 5′-TGACCA-3′ element (spanning nucleotides −118 to −113) of globin genes using its three C-terminal Zinc fingers (Znf). The binding efficiency of Znf4, Znf5, and Znf6 was predicted by using in silico tools (SIFT, SNAP, PolyPhen-2, PANTHER, I-Mutant, PROVEAN, SNPs&amp;GO, mCSM, and PhD-SNP), molecular dynamic simulation and homology modelling. K562 cells were electroporated with CRISPR-Cas9 targeting the BCL11A Znf4. Results: The binding energy scores illustrate that deleting Znf5 and Znf6 decreased the binding affinity by ~3.7-fold, whereas deleting Znf4 decreased the affinity by &amp;gt; 70-fold. Using CRISPR-Cas9 genome-editing strategy, we deleted Znf4 (260bp genomic region) within the BCL11A in K562 cell lines. Znf4 deletion resulted in a readily detectable γ-globin increase with a preferential increase in G-gamma. Conclusion: Altogether, our findings highlight the valuable insights for improving gene editing therapy strategies by either deleting Znf4 of BCL11A or the TTGACCA motif to disrupt the interaction between BCL11A and other interacting partners and the γ-globin gene promoter. Complete failure in the protein-protein interactions with functional partners and to the γ-globin gene promoter revealed that Znf4 is a suitable target for disrupting BCL11A-mediated hemoglobin switching. Citation Format: Irfan Hussain, Kainaat Mumtaz, Hammad Hassan, Afsar Ali Mian. Amelioration of hemoglobinopathies by targeted deletion of zinc finger domain within BCL11A gene using CRISPR-Cas9 technology. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4746.
Abstract 4150: Novel preclinical model for the evaluation of cytokine release syndrome in response to CD19xCD3 bispecific antibody in humanized mice
Authors: Deep S. Shah, Catalina Simion, Sang hu, Rhonda Chronis, Tre McClellan, Jae Hwang, Ryan Yang, Heather Baker, Danying Cai, James Keck, Lindsay Shopland
Journal: Cancer Research (2023)

Abstract Cytokine Release Syndrome (CRS) is a systemic inflammatory response that is caused by the large, rapid release of cytokines in the blood by immune cells affected by infection or immunotherapy and remains a prominent challenge for T cell-based therapeutics. Bispecific T cell engagers (BiTEs) are fusion proteins that are generated by linking the targeting region of two antibodies: one arm binds to the tumor-associated antigen, and the other arm binds to T cells to promote T cell-mediated cytotoxicity in an MHC-independent manner. A CD19xCD3 BiTE has been approved by the FDA for the treatment of CD19-positive B-cell lymphoma. Despite having great clinical efficacy, CRS remains a major concern for BiTE therapy. This necessitates the development of a translational model that could predict CRS toxicity more accurately. Various in-vitro models proposed to assess BiTE-related CRS have several shortcomings as they do not provide details about the systemic immune response, off-target effects, neurotoxicity, tissue damage, and organ failure. Here we propose an in-vivo approach to concomitantly assess the efficacy and CRS toxicity of CD19xCD3 BiTE either alone or in combination with Rituximab (monoclonal antibody targeting CD20) in the Raji luciferase xenograft model of Burkitt’s lymphoma in PBMC humanized NSG-MHC Class I/II knockout mice. Five days post human PBMC engraftment (Study Day- SD 5), the mice were injected with Raji-luciferase cells. On SD 6, the mice were treated with BiTE, Rituximab, or the combination of BiTE and Rituximab. Additional control groups included OKT3 and Anti-CD28, the anti-T cell antibodies that failed clinically due to severe CRS. Efficacy was assessed through in-vivo imaging on SD5, SD8, and SD11. We observed tumor growth inhibition with BiTE, Rituximab, and the combination treatment. Clinical observations were recorded daily post treatment. Following cytokines were measured 6 hours after dosing and at study termination - IL-2, IL-4, IL-6, IL-10, TNF-α, and IFN-γ. Elevated cytokine levels were observed in the BiTE/combination group 6 hours post dosing but not in the Rituximab alone group. Together, the data suggest that the model could be used to assess the preclinical efficacy and CRS toxicity of BiTE. Citation Format: Deep S. Shah, Catalina Simion, Sang hu, Rhonda Chronis, Tre McClellan, Jae Hwang, Ryan Yang, Heather Baker, Danying Cai, James Keck, Lindsay Shopland. Novel preclinical model for the evaluation of cytokine release syndrome in response to CD19xCD3 bispecific antibody in humanized mice. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4150.
Abstract 4126: Anti-tumor immunity of M9657, a conditional CD137 immune agonist, is correlated with mesothelin expression on tumor cells
Authors: Chunxiao Xu, Xueyuan Zhou, Sireesha Yalavarthi, Rene Schweickhardt, Andree Blaukat, Laura Helming
Journal: Cancer Research (2023)

Abstract Background: In clinical trials, systemic administration of first-generation CD137 agonist monotherapies was suspended due to either low anti-tumor efficacy or hepatotoxicity mediated by the epitope recognized on CD137 and Fc gamma receptor (FcγR) ligand-dependent clustering. M9657 is a bispecific conditional agonist that has been developed to bind simultaneously to mesothelin (MSLN) and CD137 to stimulate an anti-tumor immune response in the tumor microenvironment. M9657 was engineered in a tetravalent bispecific antibody (mAb2™) format with a human IgG1 backbone with LALA mutations, which abrogates binding to FcγRs but retains FcRn binding for IgG-like pharmacokinetics. M9657 is expected to have enhanced anti-tumor efficacy while avoiding systemic immune activation. Methods: MSLN surface copy number was quantified in a series of cancer cell lines with a broad range of MSLN expression. CD8+ T cell-mediated tumor cell cytotoxicity and cytokine release from CD8+ T cells were investigated in a series of in vitro functional assays. The receptor occupancy (RO) of MSLN on the tumor cell surface and of CD137 on CD8+ T cells was determined by flow cytometry. MSLN in EMT-6 cells was knocked out using CRISPR and confirmed by immunohistochemistry. The anti-tumor efficacy of FS122m, a murine-reactive surrogate of M9657, was investigated in EMT-6 parental and MSLN knockout syngeneic tumor models. Results: M9657 displayed MSLN-dependent cytokine release and tumor cell cytotoxicity. IFNγ release by CD8+ T cells correlated with MSLN copy number on tumor cells. MSLN copy number of 3000 was found to be the minimum required to trigger CD137 agonism. CD137 RO by M9657 on activated human CD8+ T cells and MSLN RO by M9657 on tumor cells increased with increasing concentrations of M9657. M9657 caused full agonism (EC100) when CD137 RO on activated human CD8+ T cells was approximately 30-38%. The mouse surrogate FS122m demonstrated potent dose-dependent anti-tumor efficacy in the EMT-6 tumor model, while no anti-tumor efficacy was observed in MSLN knockout tumors, which further confirmed that MSLN expression is required for M9657 anti-tumor immunity. Conclusion: M9657 exhibits promising and potent MSLN-dependent conditional immune agonism, supporting its clinical investigation. Citation Format: Chunxiao Xu, Xueyuan Zhou, Sireesha Yalavarthi, Rene Schweickhardt, Andree Blaukat, Laura Helming. Anti-tumor immunity of M9657, a conditional CD137 immune agonist, is correlated with mesothelin expression on tumor cells. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4126.
Abstract 3583: Novel MRI contrast system using halloysite nanotubes embedded with iron-platinum nanoparticles for the regulation of the CHST11 expression for cancer treatment
Authors: Ming-Hsien Chan, Chien-Hsiu Li, Yu-Chan Chang, Michael Hsiao
Journal: Cancer Research (2023)

Abstract Topic: TB Tumor Biology (TB03) In Vivo Imaging. Multifunctional nanocomposites have been a popular research target in recent years. This research aims to produce magnetic nanocomposites with high saturation magnetization (Ms) and good biocompatibility to improve the disadvantage of iron-oxide was easy decomposition in the biological environment and overcome the unclear contrast problem of T2-weighted magnetic resonance imaging (MRI) of lung adenocarcinoma. In order to fit the suitable size of iron-based nanoparticles embedded into the halloysite nanotubes (HNT), the iron-platinum (FePt) nanoparticles were chosen as the MRI’s core materials. The FePt@HNT nanocomposites have low toxicity, and superparamagnetism is expected to be used in biomedical therapy and magnetic separation for disease treatment and environmental protection. Lung adenocarcinoma cancer cells grow in situ, usually invade, and are frequently recurrent after treatment. Since CHST11-mediated gene regulation may serve as a possible means of reducing tyrosine kinase inhibitor (TKI)-induced mitotic cell death, CHST11 modulation of integrin signaling may help lung cancer cells enhance their resistance to gefitinib. To enable the FePt@HNT nanocomposite to be effective in treating lung tumors, we designed miRNAs that inhibit CHST11 expression in an attempt to diagnose lung adenocarcinoma concurrently for treatment. Keywords: Magnetic resonance imaging, halloysite nanotubes, FePt nanoparticles, CHST11, Lung adenocarcinoma References 1. Zhou T, Jia L, Luo YF, Xu J, Chen RH, Ge ZJ, et al. Multifunctional nanocomposite based on halloysite nanotubes for efficient luminescent bioimaging and magnetic resonance imaging. Int. J. Nanomed. 2016;11:4765-76. 2. Abdullayev E, Joshi A, Wei WB, Zhao YF, Lvov Y. Enlargement of Halloysite Clay Nanotube Lumen by Selective Etching of Aluminum Oxide. ACS Nano 2012;6:7216-26. Citation Format: Ming-Hsien Chan, Chien-Hsiu Li, Yu-Chan Chang, Michael Hsiao. Novel MRI contrast system using halloysite nanotubes embedded with iron-platinum nanoparticles for the regulation of the CHST11 expression for cancer treatment. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3583.
Abstract 514: Novel potent azetidine-based inhibitors bind irreversibly to Stat3 DNA-binding domain (DBD) and are efficacious against tumor growth in mice
Authors: Yue Chen, Ning Zhai, Yinsong Zhu, Peibin Yue, Nagendra Verma, Christine Brotherton-Pleiss, Wenzhen Fu, Kayo Nakamura, Weiliang Chen, Marcus Tius, Francisco J. Lopez-Tapia, James Turkson
Journal: Cancer Research (2023)

Abstract Unlike classical Signal transducer and activator of transcription (Stat) signaling, which is transient in non-transformed cells, the aberrant activation of the family member, Stat3, occurs in malignant transformation and is implicated in breast, ovarian and many other human cancers. Thus, Stat3 remains a validated and important target for the discovery of novel anticancer drugs. Despite this, the discovery and development of potent Stat3 small molecule inhibitors has proven to be a significant challenge, and no drug is available yet in the market. We have discovered novel Stat3 irreversible azetidine inhibitors with unprecedent submicromolar potency through systematic medicinal chemistry structure activity relationship (SAR). Mechanism of action of most potent azetidine inhibitors depend on whether they are salicylic acids or not, i.e., salicylic acids preferably bind irreversibly to Stat3 Cys426 site in the DNA-binding domain (DBD), and non-salicylic acids, e.g., current lead H182, bind to Stat3 Cys468 DBD site. As expected, the inhibition of Stat3 DNA-binding activity was time dependent, with IC50 in the range of 0.27-0.87 µM at one hour incubation with active Stat3. On the other hand, azetidine salicylic acids also bind to the SH2 domain, although reversibly and at much weaker affinity, as determined in fluorescent polarization (FP) assay, with IC50 of 10-16 µM at one hour incubation, while non-salicylic acids, e.g., lead H182, present no binding affinity up to 600 µM for the SH2 domain. Despite that H182 does not bind to SH2 domain, it still inhibits its phosphorylation. Though lead compound H182 presents significant mouse in vivo efficacy, mouse in vivo pharmacokinetics shows very low plasma AUC, which correlates with quite high mouse in vitro hepatocyte CLint of 138 µL/min/106 cells; however, human in vitro hepatocyte assay gives much better results and is in the middle stability range (CLint of 14.6 µL/min/106 cells). The in vivo PK in other species, e.g., rat, is being determined. H182 represents a plausible molecule for further development. Citation Format: Yue Chen, Ning Zhai, Yinsong Zhu, Peibin Yue, Nagendra Verma, Christine Brotherton-Pleiss, Wenzhen Fu, Kayo Nakamura, Weiliang Chen, Marcus Tius, Francisco J. Lopez-Tapia, James Turkson. Novel potent azetidine-based inhibitors bind irreversibly to Stat3 DNA-binding domain (DBD) and are efficacious against tumor growth in mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 514.
Abstract 4775: Knockout of <i>Sod2</i> accelerates <i>KrasG12D</i>-driven formation of pancreatic cancerous lesions
Authors: Alicia K. Fleming Martinez, Brandy H. Edenfield, Irene Esposito, Peter Storz
Journal: Cancer Research (2023)

Abstract Recent studies demonstrate that mitochondrially-generated reactive oxygen species (ROS) downstream of oncogenic KRAS drive acinar-to-ductal metaplasia (ADM), a key first step in the pancreatic ductal adenocarcinoma (PDA) progression model. MnSOD/SOD2 is a mitochondrial enzyme that converts superoxide into hydrogen peroxide. Previous studies have shown that SOD2 is biologically relevant to the study of pancreatic cancer. Some patients with a SOD2 polymorphism resulting in less active MnSOD at the mitochondrial matrix are at increased risk of developing pancreatic cancer. Additionally, MnSOD is lost in high-grade human PanIN, further suggesting a role in tumor development. To elucidate the role of MnSOD in pancreatic cancer initiation and progression, we crossed Sod2lox/lox mice into the p48Cre;LSL-KrasG12D (KC) mouse model. We found increased ROS, abundantly more abnormal tissue development and presence of flat lesions indicating accelerated early progression. However, Kaplan Meyer survival analysis of KC and KC;Sod2−/− mice did not indicate faster progression to cancer, suggesting that for later steps additional signaling is needed. In summary, we identify MnSOD as a key antioxidant molecule preventing initiation of PDA. Citation Format: Alicia K. Fleming Martinez, Brandy H. Edenfield, Irene Esposito, Peter Storz. Knockout of Sod2 accelerates KrasG12D-driven formation of pancreatic cancerous lesions. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4775.
Abstract 1907: Unique and novel deleterious MSH6 mutation among African American patients with colorectal cancer
Authors: Mudasir Rashid, Rumaisa Rashid, Sudhir Varma, Zaki Sherif, John Carethers, Hassan Brim, Hassan Ashktorab
Journal: Cancer Research (2023)

Abstract Background: Colorectal cancer (CRC) incidence and mortality in African Americans (AA) is higher compared to Caucasians (CAU). It has also been reported that the disparity is due to differences in the mutation spectrum particularly germline mutations in the DNA mismatch repair (MMR) genes (such as hMSH6). Aim: We aimed to determine MSH6 mutation profile in AAs with CRC. Methods: We performed RNA sequencing in 8 paired CRC samples (AA, n=4 and CAU, n=4) to identify the unique transcript and novel pathogenic mutation in AA compared to CAU by comparing CRC matched to corresponding normal epithelia. In silico analysis of TCGA COAD RNA sequencing data was performed. Results: We found non-synonymous germline mutations (p.G1139S) in exon 5 of MSH6 gene (one of the MMR genes) in AA CRC samples. Interestingly, this mutation is present in the active site of ATP binding (1135 to 11442 residue) motif of MSH6 protein. In silico analysis was used to determine the novelty and pathogenicity of this mutation by comparison to various publicly available databases. Also, the deleterious effect of p.G1139S missense mutation on the structure of MSH6 protein revealed that p.G1139S is destabilizing MSH6 protein. Based on Ramachandran plot analysis, we found lot of clash and outliers in the mutant type compared to wild type MSH6 protein. Structural analysis revealed that serine substitution results in a wide ATP binding site compared to glycine present in wild-type MSH6. In addition, we found a loss of hydrogen bonding or gain of ionic interaction between wild-type and mutant MSH6 protein. Conclusion: Based on our in silico analysis, the deleterious effect of the detected missense mutation in the active site of ATP binding motif of MSH6 affects the structure and function of MSH6. This may result in the accumulation of mono-, or di-nucleotide repeats instability in the genome, leading to genomic alterations that associate with carcinogenesis in African American CRC patients. Citation Format: Mudasir Rashid, Rumaisa Rashid, Sudhir Varma, Zaki Sherif, John Carethers, Hassan Brim, Hassan Ashktorab. Unique and novel deleterious MSH6 mutation among African American patients with colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1907.
Abstract 4222: Glyphosate and AMPA exposure: Associations with dietary intake and other factors
Authors: Rachel McFarland Lucia, Xiyue Liao, Wei-Lin Huang, Danielle Forman, Alexis Kim, Argyrios Ziogas, Trina M. Norden-Krichmar, Deborah Goodman, Andrea Alvarez, Irene Masunaka, Khyatiben Pathak, Marissa McGilvrey, Victoria David-Dirgo, Apurva Hegde, Patrick Pirrotte, Hannah Lui Park
Journal: Cancer Research (2023)

Abstract Background: Animal and epidemiologic studies suggest that exposure to the weed killer, glyphosate, and its primary metabolite aminomethylphosphonic acid (AMPA), is associated with increased risk for cancer, including breast cancer and non-Hodgkin's lymphoma. The International Agency for Research on Cancer (IARC) has categorized glyphosate as a “probable carcinogen,” yet glyphosate is the most highly used pesticide in the world. Biomonitoring studies assessing levels of human glyphosate and AMPA exposure in the United States have been limited. Thus, we examined urinary levels of these chemicals in a cohort of postmenopausal women residing in Southern California and evaluated associations with demographics, dietary intake, and other behavioral factors. Methods: 338 postmenopausal women provided two first-morning urine samples and at least one paired 24-hour dietary recall. Participants also reported on demographic and other factors. Urinary glyphosate and AMPA were measured using LC-MS/MS. Results: Glyphosate was detected in nearly 90% of urine samples and AMPA in 67.2%. Urinary glyphosate and AMPA levels were lower in women who reported high levels of organic eating (p=0.04 and p=0.01, respectively). Urinary glyphosate was lower in women who reported higher levels of physical activity (p=0.03). Multivariate analysis showed that grain consumption, particularly refined grains, was significantly associated with higher urinary glyphosate levels (adjusted p=0.004). Alcohol consumption (adjusted p=0.001) and frequency of eating fast-food (adjusted p=0.006) were associated with higher urinary AMPA levels, while fruit (adjusted p=0.03) and corn (adjusted p=0.008) consumption were associated with lower AMPA. Conclusions: In the largest study to date examining paired dietary recall data and measurements of urinary glyphosate and AMPA, the vast majority of women sampled had detectable levels. Consumption of certain foods, including grains and alcoholic beverages, were associated with higher urinary levels of glyphosate and AMPA. Citation Format: Rachel McFarland Lucia, Xiyue Liao, Wei-Lin Huang, Danielle Forman, Alexis Kim, Argyrios Ziogas, Trina M. Norden-Krichmar, Deborah Goodman, Andrea Alvarez, Irene Masunaka, Khyatiben Pathak, Marissa McGilvrey, Victoria David-Dirgo, Apurva Hegde, Patrick Pirrotte, Hannah Lui Park. Glyphosate and AMPA exposure: Associations with dietary intake and other factors. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4222.